Filter



III

Patented June 7, 1932 UNITED STATES PATENT OFFICE HOMER P. CURTIS, OFDENVER, COLORADO, ASSIGNOR OF ONE-HALF T0 J. ERNEST HIGSON, OF DENVER,COLORADO FILTER Application filed May 28, 1931.

This invention relates to improvements in filters and has reference moreparticularly to a filter intended for use in connection with oreseparation for the purpose of dewatering pulp.

In the process of separating the mineral Values from gangue the ore isground to a fine powder, usually in the presence of water, and beforethe ground ore can be shipped to a smelter, it is necessary to removethe water. In many instances the water is removed by first depositingthe ore in a bin where the water drains off after which the pulp isdried by heat. The removal of the water by the method just described isslow and very costly because the price of coal at the place where thedrying must be done is often very high.

It is the object of this invention to produce a simple and inexpensivefilter that shall be highly effective for the purpose for which it isintended and which will therefore be suitable for small mills whereexpensive filters of the usual type are inhibited due to initial cost aswell as the cost of operation.

This invention, briefly described, consists of a supporting base formedfrom a hollow member and provided at its top with an anvil. A plungerhaving a head of large diameter is located centrally of the anvil andmounted for reciprocation in a vertical direction. Means comprising acam is provided for moving the plunger upwardly with a gradual motionand then releasing it so that it will fall freely by the action ofgravity. Connected with the support is a container that is formed from acylindrical member having an imperforate bottom that is located a shortdistance from the lower end of the container. This container rests onthe anvil and is provided with a massive piston that makes a tight fitwith the cylinder walls. Sealing means is provided between the walls ofthe piston and the container and the piston is provided with an openingthat is separated from the container by means of a filter medium. Thecontainer is filled with pulp and the piston put in place after which acam is rotated so as to move the container upwardly and then release itpermitting it Serial No. 540,521.

to fall upon the anvil where it will be brought to a sudden stop. Theinertia of the piston and of the solid particles, together with theaction of gravity will put the pulp under pressure whereupon the liquidwill pass out through the opening in the piston and the solid particleswill move towards the bottom of the container.

Having thus briefly described the invention, the same will now bedescribed in de tail, and for this purpose reference will be had to theaccompanying drawing in which the preferred embodiment thereof has beenillustrated and in which:

Fig. 1 is a diametrical vertical section through the improved filter;

Fig. 2 is a bottom plan view of the piston with the screen and filtermaterial removed;

Fig. 3 is a section taken on line 35, Fig. 1; and

Fig. 4 is a section through a portion of the piston and containershowing the same to a somewhat larger scale.

In the drawing numeral 1 represents a cylindrical base to whose lowerend a flange 2 is secured. The base is adapted to be secured to asupporting surface 3 in the manner shown in the drawing. Secured to theupper end of the tubular member 1 is an anvil 4. This anvil is circularand has a downwardly extending circular flange 5 that projects into theinterior of member 1. The anvil is also provided with a downwardlyextending centrally located cylindrical portion 6 that has a centralopening 7 within which the plunger 8 is mounted for reciprocation. Theupper surface of the anvil has a circular depression for the receptionof the enlarged head 9 of the plunger. Secured to the lower end of theplunger is a steel wearing plate 10 that is held in place by means of athreaded plug 11. Extending transversely of member 1 at one side of thediameter is a shaft 12. This shaft is mounted in bearings 13 and hassecured to it a cam 14. This cam has a cylindrical surface that extendsfrom point a to point 6. The tip of the cam has been indi cated byreference character 0. The surface between points 6 and 0 is curved andthe surface between points 0 and a extends radially with respect to theshaft. The shaft and the plunger 8 are so located that a vertical planeextending through the axis of the shaft is tangent to the outer surfaceof plunger 8. Secured to one end of shaft 12 is a pulley 15 and when theshaft is rotated in the direction of the arrow, Fig. 1, the cam willoperate to move the plunger 8 upwardly until it reaches its maximumvertical position and it willthen drop freelyowing to the factthat thesurface a, c is radial as above explained. Supported on the anvil is acontainer having a cylindrical wall 16 and an imperforate bottom 17. Thebottom is located a short distance from the lower end'of the cylindricalwall 16 and is adapted to rest on the top of t-he'anvil. Located withinthe container is a piston 18. This piston is quite heavy and is providedon its underside with four transa verse grooves 19 that intersect at thecenter.

The center is provided with an opening 20 into the upper end of which ahollow plug 21 is threaded. A ball 22 is located within the hollow plugand forms a check valve. Secured tothe upper end of the plug is a hose23. The'lower surface of the piston has clownwardly extending angularshoulder 2% and has secured to it a heavy wire screen 25 that is held inplace by means of screws 26. The surface between the transverse grooves19 is provided with a plurality of concentric grooves 27. The lowerouter'edge of the'piston surface is chamfered as indicated by 28 andthis chamfered portion is adapted to receive a rubber ring 29 that formsa seal. A filter cloth 30 is interposed between the lower surface of thepiston and the contents of the container. The container is provided withtwo diametrically located lugs 21 to which a bail 22 is connected.

Let us now assume that the apparatus described above and shown on thedrawing is assembled and that the container is partly filled with a pulpand that the piston is resting on the upper surface of this pulp. Vhenthe shaft is rotated, the container and its contents will be graduallyraised due to the cam action and after the tip of ,thecam passesbeyondthesurface of plate 10,'the container will drop freely under theaction of gravity and will be'brought to a sudden stop when it strikesthe upper surface of the anvil. During the fall of the container thepiston as well as the pulp attain a certain velocity. hen the containeris brought to a sudden stop, the inertia or momentum of the piston'willtend to move this downwardly and by thisaction the pulp will'besubjected to considerable pressure that will force the liquid throughthe filter medium and into the hose 23. The sudden stoppage of thecontainer alsotendsto effect a separation between the liquid and theheavier solid particles suspended in the liquid because the momentum 5and inertia'of the particles will tend tomove them downwardly throughthe liquid after the container has been brought to a stop and in thisway a selective separation takes place, that brings the heavierparticles to the bottom. The continued operation of the filter providedthat vibrates the container until the filtrate is loosened and dropsfrom it. This mechanism has not been shown because it constitutesanother invention.

It will be seen from theabove description that the filter shown on thedrawing and described herein is exceedingly simple and that it cantherefore be made at a comparatively small cost. Only a small amountofpower is required to operate it and it is therefore especially welladapted for use in mills located at mines far removed from sources ofcheap power and is therefore suitable 'for the smaller mills where thecost of equipment and of operation is an item that must be given carefulconsideration.

Although a single machine has been shown, it is to be understood that amill .is usually provided with a large number that can be connected tothe same shaftor interconnected in any suitable manner.

Having described the invention what is claimed as new is:

1. A filter comprising, in combination, a container having animperforate bottom and adapted to contain a liquid containing solidparticles in suspension, means for gradually raising the container andfor releasing the same so that it may fall by the action of gravity anda stop for bringing the container 'to a sudden stop whereby the solidparticles of the liquid will continue to move downwardly in the liquidby the combined action of their inertia and the action of gravity.

2. A filter comprising, in combination, a container having animperforatebottom, and adapted to contain a liquid having solidparticles in suspension therein, means for supporting the container,means for gradually raising the container and for releasing it at thetop'of its movement whereby it may fall under the influence of gravity,a stop'for suddenly interrupting the movement of the container wherebythe solid particles suspended in the liquid will continue to movedownwardly due to the combined action of gravity and their momentum, andmeans for removing liquid from the container.

3. A filter comprising, in combination, a container having animperforate bottom and cylindrical walls, said container being adaptedto contain a liquid having solid particles suspended therein, a pistonlocated in the container and adapted to be supported by the contentsthereof, said piston having an opening for the escape of the liquid, afilter medium interposed between the opening and the interior of thecontainer, a support for the container and means for gradually liftingthe container from the support and then releasing it so that it willfall freely under the action of gravity whereby it will strike thesupport and stop suddenly thereby subjecting the contents of thecontainer to pressure produced by the inertia of the piston and wherebythe solid particles will be moved towards the bottom by the combinedaction of gravity and their own inertia.

4. A filter comprising a support, a plunger carried thereby and mountedfor movement in a vertical direction, means comprising a cam for movingthe plunger upwardly by a gradual movement and then releasing it so thatit can fall freely under the influence of gravity, a cylindricalcontainer having an imperforate bottom, a portion of the wall of thecontainer projecting beneath the bottom and forming a guide and amassive piston located within the container.

5. A filter comprising a support, a plunger carried thereby and mountedfor movement in a vertical direction, means comprising a cam for movingthe plunger upwardly by a gradual movement and then releasing it so thatit can fall freely under the influence of gravity, a cylindricalcontainer having an imperforate bottom, a portion of the wall of thecontainer projecting beneath the bottom and forming a guide, a massivepiston located within the container, and sealing means between the wallsof the container and the pisten.

6. A filter comprising a support, a plunger carried thereby and mountedfor movement in a vertical direction, means comprising a cam for movingthe plunger upwardly by a gradual movement and then releasing it so thatit can fall freely under the influence of gravity, a cylindricalcontainer having an imperforate bottom, a portion of the wall of thecontainer projecting beneath the bottom and forming a guide, a massivepiston located within the container, and sealing means between the wallsof the container and the piston, the piston having an opening extendingthrough it, and a filter medium interposed between the interior of thecontainer and the opening.

7. A filter comprising a support, a plunger carried thereby and mountedfor movement in a vertical direction, means comprising a cam for movingthe plunger upwardly by a gradual movement and then releasing it so thatit can fall freely under the influence of gravity, a cylindricalcontainer having an imperforate bottom, a portion of the wall of thecontainer projecting beneath the bottom and forming a guide, a massivepiston located within the container, and sealing means between the wallsof the container and the piston, the lower surface of the piston havinga plurality of grooves communicating imperforate bottom, a portion ofthe wall of the container projecting beneath the bottom and forming aguide and a massive piston located within the container, the lower edgeof the wall of the piston having a chamfer, an a sealing ring located inthe chamfer.

In testimony whereof I aflix in signature.

HOMER P. C IURTIS.

